Method for sealingly interconnecting a pipe with a structure such that the pipe is axially movable with respect thereto

ABSTRACT

A method is provided for interconnecting an end of a pipe with a hollow structure having a screw-threaded tubular inlet thereto. The method includes applying a one-part annular sealing member around the pipe, wherein the annular sealing member has a screw-threaded portion for engagement with the screw-threaded tubular inlet and is provided with the first and second sealing means; distorting outwardly the end of the pipe around at least a portion of the periphery thereof; and effecting screw-threaded engagement between the annular sealing member and the tubular inlet, such that sealing engagement is effected between the annular sealing member and the pipe end over a plurality of relative axial positions therebetween. The first sealing means effects sealing engagement between the annular sealing member and the inlet, and the second sealing means effects sealing engagement between the annular sealing member and the pipe end. Axial movement of the pipe relative to the annular sealing member is permitted when the annular sealing member is in sealing engagement with the pipe end.

This invention relates to joints and in particular to joints and handtools for connecting a pipe or other tubular elements to a hollowstructure having a tubular inlet thereto.

Joints of the type with which this invention is concerned have manyapplications, examples being joints for use in connection with centralheating systems, air conditioning systems, vehicles, white goods, petrolpumps, fire fighting equipment, heater batteries, tank fittings andthree way valve systems.

Current joints of the type with which this invention is concerned arenormally such that they are difficult to install and a major reason forthis is that they do not allow relative axial movement between the pipeand the hollow structure to which the pipe is to be connected.

According to the present invention there is provided a method ofinterconnecting an end of a pipe with a hollow structure having ascrew-threaded tubular inlet thereto, the method comprising applying anannular sealing member around the pipe, said annular sealing memberhaving a screw-threaded portion for engagement with the screw-threadedtubular inlet and being provided with first and second sealing means,said first sealing means being for sealing engagement between saidannular sealing member and said inlet and said second sealing meansbeing for sealing engagement between said annular sealing member andsaid pipe end, distorting outwardly the end of the pipe around at leasta portion of the periphery thereof, and effecting screw-threadedengagement between the annular sealing member and the tubular inlet,whereby sealing engagement may be effected between said sealing memberand said pipe and over a plurality of relative axial positionstherebetween.

Accordingly, a joint formed by a method allows relative axial movementbetween the members to be joined together. Such an arrangement allowseasy positioning of the members into their appropriate positionsrelative to each other and subsequent operation to form an effectivejoint between the members.

The annular sealing member is a single member provided with means foraccommodating the first and second sealing means as well as a screwthreaded portion or other means for engaging the tubular inlet. Theannular sealing member may also be provided with a recess so as toaccommodate a protrusion or crimp or upset of a pipe. The recess ispreferably substantially continuous about the periphery of the pipe.

The first and second sealing means may be any suitable sealing elements,for instance, O-rings.

The sealing member and the pipe may be put into sealing engagement witheach other over a plurality of discrete relative axial positions or overa continuous range of positions therebetween. Preferably, the pipe isprovided with some form of radially and outwardly extending protrusionwhich limits the range of axial positions due to engagement between saidprotrusion and another element of the joint, for instance, the annularsealing member.

In another embodiment of the invention the pipes provided with tworadially and outwardly extending protrusions. Preferably, the first ofsaid protrusions protrudes a sufficient distance about the periphery ofa pipe so as to engage with the joint of the invention and prevent thepipe from being pulled out of engagement with same. More preferably saidfirst protrusion is suitable located a relatively short distance fromthe end of the pipe. Preferably, the second protrusion is relativelysmall with respect to the first protrusion, and more preferably stillsaid second protrusion is of marginally smaller dimensions than therecess portion in the annular sealing member. Thus, in use and inposition, said second protrusion is accommodated within the recessportion of the annular sealing member and is allowed sufficient movementtherein so as not to impede rotational movement of the pipe.

It will be appreciated that provision of two protrusions, the firstprotrusion acting as a pipe-stop just outside the joint itself, and thesecond protrusion being loosely accommodated within the joint itself,allows for limited axial movement whilst providing a secure joint.

The invention also provides a joint for use in the method of theinvention, the joint being as defined above in connection with saidmethod.

There may also be provided with the joint a tool comprising means fordistorting or crimping or flaring the end of a pipe. Ideally the tool ismanually operated and the tool may be of a scissors type or a clampingtype action. In the scissors type embodiment, the tool comprisespivotally connected upper and lower jaws, wherein the lower jaw hascorresponding recesses into which spikes or ribs of the upper jaw fitwhen the jaws are closed together about at least a part of a pipe.Alternatively the tool comprises a clamp, wherein an upper surface ofsaid clamp is provided with recess portions and a lower surface isprovided with corresponding spikes or ridges or the like which fit intothe recesses in a clamped position. In use, the pipe is sandwichedbetween the two clamping surfaces or scissors jaws and sufficient forceis applied so as to impart a crimp or ridge or groove onto the pipesurface.

Embodiments of the invention will now be described, by way of examplesonly, and with reference to the accompanying drawings, in which:

FIG. 1 shows a cross-section through a first embodiment of a joint ofthe invention;

FIG. 2 shows an embodiment of FIG. 1 but with different relative axialpositions between the members of the drawing;

FIG. 3 shows a cross-section through a second embodiment of a joint ofthe invention;

FIG. 4 shows a cross-section through a third embodiment of a joint ofthe invention;

FIG. 5 shows a cross-section through a fourth embodiment of a joint ofthe invention;

FIG. 6 shows a cross-section through a fifth embodiment of a joint ofthe present invention;

FIG. 7 shows a cross-section through a sixth embodiment of a joint ofthe invention;

FIG. 8 shows a cross-section through a seventh embodiment of a joint ofthe invention;

FIG. 9 shows a tool for distorting or crimping the end of a pipe for usewith a joint of the present invention;

FIG. 10 shows an alternative embodiment of a tool for distorting orcrimping the end of a pipe for use with a joint of the presentinvention;

FIG. 11 shows a cross-section through a ninth embodiment of a joint ofthe invention;

FIG. 12 shows the tool of FIG. 10 placed about the joint of FIG. 11 atthe start of the procedure to distort or crimp the end of a pipe; and

FIG. 13 shows progression of FIG. 12.

Referring to FIGS. 1 and 2 of the accompanying drawings, a joint 1 liesbetween a pipe receiving fitting 3 of a central heating radiator and aradiator valve (not shown). Pipe receiving fitting 3 is in the form of ahollow sphere 5 from which a short tubular inlet 7 extends. The fitting3 is provided with a short length of pipe (not shown) integral therewithand which is welded to the body of the radiator (not shown). Tubularinlet 7 is threaded on its inner surface.

The joint comprises two parts, an annular sealing member 9 and a tubularmember 11.

The annular sealing member 9 is in the form of a short tube of which afirst portion 11 has a relatively thick tubular wall and is providedwith a threaded outer surface which is for engagement with the threadedinner surface of inlet 7 of pipe receiving fitting 3.

Over the rest of its axial length, annual sealing member 9 has arelatively thinner wall which is stepped axially to provide two O-ringaccommodating portions 13 and 15.

As seen in FIGS. 1 and 2, O-ring accommodating portion 13 is in the formof an outwardly facing recess which is shaped and dimensioned so as tohold an O-ring 17 and allow it to be compressed against the radial endsurface 19 of inlet 7 of fitting 3. This is achieved by the recess 13being provided with two spaced apart radial walls, the radial wallremote from inlet 7 extending radially outwardly beyond the inner radialwall. As a result the O-ring 17 can be trapped between the outer radialwall and the surface 19, as illustrated in FIGS. 1 and 2.

The second O-ring accommodating portion 15 lies adjacent the firstO-ring accommodating portion and is in the form of a recess facingradially inwardly. This recess accommodates a second O-ring 21 which isfor sealing engagement between the annular sealing member 9 and thetubular member 11.

Tubular member 11 is provided with a radially outwardly directed endflange 23 which may be formed by deforming the end of a uniform tubularmember.

In order to form a secure joint between a pipe having associatedtherewith tubular member 11 and the pipe receiving fitting 3, thetubular member 11, having the annular sealing member 9 positionedthereabout, is introduced into inlet 7. The outer threaded portion ofannular sealing member 7 is brought into engagement with the innerthreaded section of inlet 7 and annular sealing member 9 is turned untilO-ring 17 is compressed between the annular sealing member and the inlet7. At this position, O-ring 21 is in firm sealing engagement withtubular member 11.

FIG. 2 illustrates the same joint but with the tubular member 11 shownin a different axial position relative to pipe receiving fitting 3.FIGS. 1 and 2 illustrate the full range of axial positions betweenmember 11 and fitting 3, thereby allowing for ease of fitting of thejoint and for the accommodation of different relative positions betweenthe pipe and the radiator to which it is to be connected.

It should be appreciated that the use of the joint such as thatdescribed above allows the central heating radiator to be rotatedrelative to the pipes to which it is connected since fitting 3 may berotated with annular sealing member 9 about tubular member 11.Accordingly such joints provided between two coaxilly aligned valves ofa radiator allow the radiator to be lifted and hingedly lowered to giveaccess to the wall there behind for maintenance and decoration withoutuse of tools or loosening any plumbing connection.

Referring now to FIG. 3 of the accompanying drawings, a secondembodiment of a joint in accordance with the present invention issimilar to the embodiments shown in FIGS. 1 and 2, the main differencebeing that the annular sealing member 71 carries an internal threadedsection 73. Tubular inlet 75 carries an outwardly facing threadedsection 77 for engagement with section 73 of annular sealing member 71.

Referring to FIG. 4 of the accompanying drawings, a third embodiment ofa joint of the present invention is shown in use providing sealing of,for instance, an outlet pipe 81 into the wall 83 of a tank. In this casethe annular sealing member 85 is in the form of a short tube of which afirst portion 87 is shaped to provide an internal recess foraccommodating an O-ring 89. Extending longitudinally from portion 87 isan externally threaded portion 91. As illustrated in FIG. 5, annularsealing member 85 surrounds pipe 81 with O-ring 89 in sealing engagementwith the wall of pipe 81.

A further O-ring 93 is located around threaded portion 91 adjacentO-ring accommodating portion 87.

The joint is mounted into the tank wall with threaded portion 91 beingin threaded engagement with a backing nut 95 welded to the rear of thetank wall 83 about the entry hole therein.

Pipe 81 is provided with an outwardly extending flange or crimpedportion 97 which might be continuous or discontinuous around theperiphery of the pipe. This portion 97 prevents the pipe from beingpulled out of engagement with the joint. However subject to thislimitation, axial movement between the pipe and the joint is possible.

An advantage of a tank joint as described above is that the inlet pipemay be fitted to the bottom of the tank and then pushed up into the tankto provide a clearance between the bottom of the tank and the end of thepipe of an appropriate amount, say of the order of 5 cm. With currentlyavailable arrangements, the inlet is provided in the side of the tankbecause no axial movement is possible between the pipe and the tank.

Referring to FIG. 5 of the accompanying drawings, there is illustrated ajoint for interconnecting two pipes 101 and 103. The joint include asubstantially tubular member 105 which has two externally threadedportions 107 and 109, longitudinally separated from each other.Internally tube 105 includes a central section 111 of relatively smalldiameter and stepped outwardly therefrom at each end thereof, pipeaccommodating portions 113 and 115 of somewhat larger diameter.

As shown in FIG. 5, each pipe end 101 and 103 is provided with anoutwardly directed flange 117 which extends about the periphery of thepipe end and is located a short distance from the very end of the pipe.

The joint is provided with a pair of annular sealing members 119, 121.Each annular sealing member is associated with a respective pipe end andeach has an internally threaded section 123 for engagement with arespective threaded section of tube 107. Adjacent the threaded sectionis located an O-ring 125 which is for sealing between the end of thetube 107 and the annular sealing member 119 or 121.

Longitudinally adjacent O-ring 125 is an internally facing channel orrecess 127 provided on the annular sealing member 119 or 121. Locatedwithin recess 127 is a further O-ring 129 providing sealing between theannular sealing member and the pipe.

It can be seen that, with pipes 101 and 103 located in position, asshown in FIG. 6, within respective annular sealing members 107 and 109and with the latter tightened on threaded tube 105, sealing is providedbetween the two pipe ends via the annular sealing members and thecentral tube.

Referring now to FIG. 6 of the accompanying drawings, a joint forconnecting together two pipes 131, 135 is similar to that described inconnection with FIG. 5 except that there is associated with each pipeend only a single sealing ring 135 which, as shown in FIG. 7, is, inuse, squeezed between the pipe end, the central threaded tube 137 andthe respective annular sealing member 139 or 141.

Referring to FIG. 7 of the accompanying drawings, a joint is shown forsealing between two pipes disposed at angles to each other, in this caseat a right angle to each other. The essential difference between thisjoint and that of FIG. 7 is that the central tube 143 includes a rightangle turn.

Referring now to FIG. 8 of the accompanying drawings, there is hereshown an arrangement similar to that of FIGS. 7 and 8 except that it isfor use in connecting together three pipes and makes use of a T-junctioncentral member 145 having three threaded ends, each said end for matingwith a corresponding annular sealing member.

Referring to FIG. 9 of the accompanying drawings, there is depicted asimple tool for distorting or crimping the end of a pipe for use inconnection with one of the above described joints of the presentinvention. The tool is a manual, scissor-action implement having handles121 and 123 which are pivotally connected together and from which extendupper and lower jaws 125 and 127. Upper jaw 125 is provided with adownwardly extending spike or rib 129. Lower jaw 127 is provided with acorresponding recess 131 into which spike or rib 129 fits when the jawsof the implement are closed together.

With the pipe end placed between the jaws 125, 127 of the implement, thejaws may be manually caused to come together and pressure exerted on thehandles of the implement will cause the spike or rib 129 to deform thepipe near its end to form an outwardly extending deformation on the pipeend. The deformation may be a single deformation, a series ofperipherally spaced apart deformations or, by running the tool aroundthe pipe end, a continuous peripheral distortion.

With reference to FIG. 10 there is shown an alternative embodiment tothe tool of FIG. 10. In this particular embodiment the tool 146 operatesby a clamping mechanism, the force being applied by turning of screwthreaded means 145. Lower clamping surface 147 is provided withprotrusions 149 and 150 and upper clamping surface 148 is provided withcorresponding recesses 151 and 152. Protrusion 150 is spiked so as toprovide significant deformation to a pipe when clamped about a pipe, inorder that a ridge of sufficient dimensions is formed that is capable ofabutting the end of the annular sealing member and preventingdisengagement of the joint. Protrusion 149 is of relatively smallerdimensions and is intended to provide the pipe with a relatively lessprominent ridge or deformation following clamping about the pipe.

Referring to FIG. 11 there is shown a ninth embodiment of a joint inaccordance with the present invention, which is similar to theembodiments shown in FIGS. 4 and 5, in that the annular sealing member153 carries an internal threaded section 154. The main difference beingthe provision of a recess portion 155, the recess portion is provided onthe innermost surface of the annular sealing member, that surface beingin contact with the pipe 156 and close to the end of the threadedsection 154.

With reference to FIGS. 12 and 13, there is shown the tool 146 of FIG.10, placed about the pipe and joint of FIG. 11 at a preliminary stage inthe process of crimping or deforming or grooving the pipe 156. Upperclamping surface 148 is allowed to rest on the outer surface 157 of thepipe and is located by abutting the end of the pipe against an innersurface 158 of the tool. Once in position, clamping force is applied byturning the threaded screw means 145. The clamping force is continuallyapplied (with reference to FIG. 13) until the two protrusions on thelower clamping surface are positioned in their corresponding recesses inthe upper clamping surface thereby effectively sandwiching the pipetherebetween. As a result of the applied clamping force the pipe isappropriately deformed so that it has the first and second protrusionsimparted thereon.

The joint and tool of the present invention therefore presents a noveland elegant means for connecting a pipe or other tubular element to ahollow structure such as a water tank or the like, having a tubularinlet thereto. It also provides a joint that is easy to install andprovides some relative axial movement for ease of maintenance and thelike whilst maintaining a strong and effective connection.

What is claimed is:
 1. A method of interconnecting an end of a pipe witha hollow structure having a screw-threaded tubular inlet thereto, themethod comprising: applying a one-part annular sealing member around thepipe, said annular sealing member having a screw-threaded portion forengagement with the screw-threaded tubular inlet and being provided withfirst and second sealing means, said first sealing means being forsealing engagement between said annular sealing member and said inletand second sealing means being for sealing engagement between saidannular sealing member and said pipe end, and wherein axial movement ofsaid pipe relative to said annular sealing member is permitted when saidannular sealing member is in sealing engagement with said pipe end,distorting outwardly the end of the pipe around at least a portion ofthe periphery thereof, and effecting screw-threaded engagement betweenthe annular sealing member and the tubular inlet, such that sealingengagement is effected between said annular sealing member and said pipeend over a plurality of relative axial positions therebetween.
 2. Amethod according to claim 1 in which the annular sealing member isprovided with a recess to accommodate the outwardly distorted portion ofthe pipe end.
 3. A method according to claim 2 wherein the recess issubstantially continuous about the periphery of the pipe.
 4. A methodaccording to claim 1 wherein one or both of the first and second sealingmeans is an O-ring.
 5. A method according to claim 1 in which theannular sealing member and the tubular member are such that they may beput into seal engagement with each other over a plurality of discreterelative axial positions or over a continuous range of positionstherebetween.
 6. A method according to claim 1 in which the annularsealing member and the tubular member are such that they may be put intosealing engagement with each other over a continuous range of relativeaxial positions therebetween.
 7. A method according to claim 1 in whichthe tubular pipe is provided with two longitudinally-spaced and radiallyand outwardly extending protrusions.
 8. A method according to claim 1wherein said first and second sealing means are provided by respectivefirst and second sealing members.
 9. A method according to claim 1wherein said first and second sealing means are provided by a singlesealing member.